1. Field of the Invention
The present invention relates to an image forming apparatus, such as a copier, having a display portion for displaying the working condition thereof, and more specifically, to an image forming apparatus in which the display portion visually changes in response to the change of the working condition of the apparatus.
2. Description of the Related Art
For various kinds of image forming apparatuses, various technical proposals have previously been made with an object of enhancing the operation efficiency of the apparatus and improving the operability and the viewability of the display panel that forms the heart of the man-machine interface with the user.
For example, Japanese Unexamined Patent Publication JP-A 11-275290 (1999) proposes an apparatus in which no error indicating means is required because an error indication for notifying the user of an occurrence of an error such as an image reading error is provided by changing the color of the light emitted by a reading light source of image reading means.
Japanese Unexamined Patent Publication JP-A 6-110033 (1994) discloses a technology with an object of improving the display brightness and resolution of the liquid crystal display by successively emitting lights of the three primary colors of a back light source and realizing multicolor display with one pixel.
Japanese Unexamined Patent Publication JP-A 5-323905 (1993) discloses a technology associated with a color conversion processing in which by providing a color converter that generates an I signal (white pixel signal) from an RGB signal, the characteristic of display means including an I pixel can be used with the conventional CRT signal as it is.
Many of the display panels of conventional image forming apparatuses are of formats displaying mainly characters such as characters necessary for the user to operate the apparatus and characters representative of the operation status of the apparatus. Such display panels displaying characters frequently use color liquid crystal because it is necessary to read the displayed characters.
For example, Japanese Unexamined Patent Publication JP-A 5-131727 (1993) makes a proposal with an object of, in a printer having the function of displaying the printing contents relating to a display device, improving the operability and the maintainability by providing color display without the use of an additional storage device and enabling not only the printing contents but also an error indication, a warning indication, a maintenance indication and the like to be displayed on the display device by changing the hue.
Japanese Unexamined Patent Publication JP-A 5-313455 (1993) describes a display device in which color filters capable of being freely inserted into and taken out of a gap between the liquid crystal display panel and the back light are provided as abnormality notifying means for notifying the user of an occurrence of an abnormality of the apparatus, and by superimposing on one another a plurality of such color filters having different hues, indications providing a warning and attracting the user's attention can be displayed on the same screen by an operation of the color filters.
However, in the cases of JP-A 5-131727 and JP-A 5-313455, merely the process or the condition of the copier (for example, the copier is on standby or printing, or a trouble occurs) is displayed in color, and the user cannot obtain detailed information necessary for the user such that in each process, what working condition the apparatus is in and which functions are usable at present.
Particularly, networked copiers that have been increasing in recent years have a problem (inferiority in usability) such that although the apparatus is operating, since the user is uncertain when to apply an interrupt, to use a desired function, the user must wait until the apparatus stops.